Sulfur asphalt in roofing, damp-proofing and water proofing

ABSTRACT

A method of waterproofing or damp proofing a protected member having a surface with a sulfur-extended elastomer asphalt binder composition uses a sulfur-extended elastomer asphalt binder composition that includes elemental sulfur, an elastomer and an asphalt binder. The method includes the steps of combining the elastomer with the asphalt binder maintained at an elastomer mixing temperature such that an intermediate asphalt binder mixture forms, and combining elemental sulfur with the intermediate asphalt binder maintained at a sulfur mixing temperature such that the sulfur-extended elastomer asphalt binder composition forms. The method also includes the step of applying the sulfur-extended elastomer asphalt binder composition to the surface of the protected member such that the sulfur-extended elastomer asphalt binder composition contacts, adheres to and forms a layer upon the surface of the protected member. The asphalt binder composition is applied at a temperature no greater than 145° C.

CROSS REFERENCE TO RELATED APPLICATION

This application is a continuation of, and claims priority to and thebenefit of, co-pending U.S. application Ser. No. 14/069,919, filed Nov.1, 2013, titled “Sulfur Asphalt In Roofing, Damp-Proofing And WaterProofing,” the full disclosure of which is hereby incorporated herein byreference in its entirety for all purposes.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The field of invention relates to asphalt compositions for roofing,damp-proofing and water proofing and their use. More specifically, thefield relates to sulfur-extended elastomer asphalt binders (SEEABs).

2. Description of the Related Art

During the manufacturing and processing of materials containing asphaltsuch as asphalt-coated aggregates and hot asphalt mixes, workingtemperatures above 300° F. can cause problems for workers and theirequipment. At temperatures greater than 300° F., sulfur and sulfurcompounds present in asphalt or bitumen mixes, including elementalsulfur and naturally present heteroatom organic compounds, begin toreact with other constituents in the asphalt and with the oxygen in theair. One of the main products of these reactions is hydrogen sulfidegas, where free sulfur in hydrocarbon environments dehydrogenateshydrocarbons and forms hydrogen sulfide. Hydrogen sulfide in lowquantities is an irritant but in high quantities it is toxic. Heatedsulfur that oxidizes in the air forms sulfur dioxide. Sulfur dioxide hasa noxious odor and is considered an air pollutant. Working in elevatedconditions, including on top of metal roofing, or in confinedconditions, including basements and pits, can concentrate and exacerbatethe exposure to these unwanted byproducts. It is desirable to find anasphalt composition that is workable at temperatures below 300° F. forworker comfort and safety in addition to not releasing noxious chemicalsinto the environment.

Sulfur, especially “free” or elemental sulfur, is an abundant andinexpensive material. Elemental sulfur is a byproduct of non-sweetnatural gas and petroleum processing. Sources of free sulfur includepetroleum refineries and gas sweetening plants. Because of the quantityof sulfur extracted annually from natural gas and petroleum processes,many sulfur producers consider elemental sulfur a “waste” product.Others have attempted to use waste sulfur as an expander or filler forasphalt and bitumen compositions but only have obtained limited success.Therefore, it is also desirable to find commercial uses for elementalsulfur. Incorporating sulfur into commercial products can transform whatmany consider a waste product into a product that has practical value asan expander of the hydrocarbon resource supply.

SUMMARY OF THE INVENTION

A sulfur-extended elastomer asphalt binder composition that is usefulfor water proofing, damp proofing and roofing applications includeselemental sulfur, an elastomer and an asphalt binder. Thesulfur-extended elastomer asphalt binder composition includes elementalsulfur in a range of from about 0.1% to about 30.0%, the elastomer in arange of from about 0.1% to about 10.0% and the asphalt binder in arange of from about 99.8% to about 60%, each by total weight.

A method of waterproofing or damp proofing a protected member having asurface with a sulfur-extended elastomer asphalt binder compositionincludes a step of combining the elastomer with an asphalt bindermaintained at an elastomer mixing temperature such that an intermediateasphalt binder mixture forms. The method also includes the step ofcombining elemental sulfur with the intermediate asphalt bindermaintained at a sulfur mixing temperature such that the sulfur-extendedelastomer asphalt binder composition forms. The sulfur-extendedelastomer asphalt binder composition comprises elemental sulfur in arange of from about 0.1% to about 10.0%, the elastomer in a range offrom about 0.1% to about 30.0%, and the asphalt binder in a range offrom about 99.8% to about 60%, each by total weight. The method alsoincludes the step of applying the sulfur-extended elastomer asphaltbinder composition to the surface of the protected member such that thesulfur-extended elastomer asphalt binder composition contacts and formsa layer upon and adheres to the surface of the protected member. Theasphalt binder composition is applied at a temperature in a range offrom about ambient temperature to no greater than 145° C. The formedlayer is operable to prevent water migration through the protectedmember. The formed layer has a first side in contact with and bonded tothe surface of the protected member and a second side that does notcontact the surface of the protected member. The bonded layer has a bondstrength with the surface of at least about 150 kiloNewtwons per metersquared (kN/m²) as determined using the Bond Strength Test.

BRIEF DESCRIPTION OF THE DRAWINGS

No figures.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The Specification, which includes the Summary of Invention, BriefDescription of the Drawings and the Detailed Description of thePreferred Embodiments, and the appended Claims refer to particularfeatures (including process or method steps) of the invention. Those ofskill in the art understand that the invention includes all possiblecombinations and uses of particular features described in theSpecification. Those of skill in the art understand that the inventionis not limited to or by the description of embodiments given in theSpecification. The inventive subject matter is not restricted exceptonly in the spirit of the Specification and appended Claims.

Those of skill in the art also understand that the terminology used fordescribing particular embodiments does not limit the scope or breadth ofthe invention. In interpreting the Specification and appended Claims,all terms should be interpreted in the broadest possible mannerconsistent with the context of each term. All technical and scientificterms used in the Specification and appended Claims have the samemeaning as commonly understood by one of ordinary skill in the art towhich this invention belongs unless defined otherwise.

As used in the Specification and appended Claims, the singular forms“a”, “an”, and “the” include plural references unless the contextclearly indicates otherwise.

As used, the words “comprise,” “has,” “includes”, and all othergrammatical variations are each intended to have an open, non-limitingmeaning that does not exclude additional elements, components or steps.Embodiments of the present invention may suitably “comprise”, “consist”or “consist essentially of” the limiting features disclosed, and may bepracticed in the absence of a limiting feature not disclosed. Forexample, it can be recognized by those skilled in the art that certainsteps can be combined into a single step.

Where a range of values is provided in the Specification or in theappended Claims, it is understood that the interval encompasses eachintervening value between the upper limit and the lower limit as well asthe upper limit and the lower limit. The invention encompasses andbounds smaller ranges of the interval subject to any specific exclusionprovided.

Where reference is made in the Specification and appended Claims to amethod comprising two or more defined steps, the defined steps can becarried out in any order or simultaneously except where the contextexcludes that possibility.

When a patent or a publication is referenced in this disclosure, thereference is incorporated by reference and in its entirety to the extentthat it does not contradict statements made in this disclosure.

Sulfur-Extended Elastomer Asphalt Binder

The sulfur-extended elastomer asphalt binder (SEEAB) is made bycombining the asphalt binder, elemental sulfur and the elastomer. Thesulfur-extended elastomer asphalt binder is a combination of elementalsulfur in a range of from about 0.1% to about 30.0%, the elastomer in arange of from about 0.1% to about 10.0% and the asphalt binder in arange of from about 99.8% to about 60%, each by total weight of thesulfur-extended elastomer asphalt binder composition. An embodiment ofthe SEEAB includes where the elemental sulfur is in a range of fromabout 0.1% to about 10.0% and the asphalt binder is in a range of fromabout 99.8% to about 80%, each by total weight of the sulfur-extendedelastomer asphalt binder composition.

An embodiment of the sulfur-extended elastomer asphalt bindercomposition consists essentially of elemental sulfur, elastomer andasphalt binder. An embodiment of the composition consists essentially of5.0% elemental sulfur, 5.0% the elastomer and 90.0% the asphalt binder,each by total weight of the sulfur-extended elastomer asphalt bindercomposition.

Asphalt Binder

Bitumen and asphalt that are useful as the asphalt binder can originatefrom petroleum distillation (for example, vacuum tails); coal, tar sandsor oil shale processing; or from naturally occurring sources (forexample, Trinidad Lakes). The base asphalt material can be a singularmaterial or a blend of several base asphalts.

Asphalt and bitumen is a colloidal dispersion of asphaltenes in amaltenes phase. Asphaltenes include clusters of large polycyclicaromatic molecules. The structure of asphaltenes may include, in noparticular order or regularity, cyclo-alkanes, cyclo-alkenes, and alkaneand alkene chains extending from polycyclic molecules for up to 30carbons (C₃₀) in length. Asphaltenes can also have functional moietiesthat are capable of reacting with other materials. Functional moietiesinclude alcohols, carboxylic acids, ketones, phenols, amines, amides,sulfides, sulfoxides, sulfones, sulfonic acids, and porphyrin ringschelated with vanadium, nickel, and iron. Asphaltenes also haveheterorganic aromatic rings part of their overall polycyclic structure,including benzothiophene, pyrrole and pyridine rings.

The maltenes phase, which is more mobile than the asphaltene phase,includes asphaltene resins, polar and non-polar aromatics, cyclicsaturated hydrocarbons (for example, naphthenes), and both straight andlong-chain saturated hydrocarbons. Although not intending to be bound bytheory, it is believed that polar aromatics in the maltene phase tend tobe the dispersing agent for the asphaltenes, interacting with polarfunctional groups that can exist on asphaltenes. Maltenes can bepartially extracted from the dispersion using an n-alkane-based solvent;asphaltenes cannot.

All asphalt and bitumen are suitable as the asphalt binder. Asphalteneconcentration varies in amount and functionality depending on the sourceof the bitumen. The asphaltene content of the asphalt is typically inthe range of from about 0.01% by weight to about 30% by weight of thematerial. An embodiment of the sulfur-extended elastomer asphalt bindercomposition includes using “Performance Graded” binders based upon theproperties listed in the Performance Grade table (“Table 1”) of theAASHTO Performance Graded Asphalt Binder Specification M 320 as theasphalt binder. An embodiment of the asphalt binder composition includeswhere the asphalt binder comprises a PG 64-10 asphalt binder. Anembodiment of the asphalt binder composition includes where the asphaltbinder consists essentially of a neat PG 64-10 asphalt binder.

Elemental Sulfur

The elemental or “free” sulfur includes not only singular sulfur atomsbut also sulfur in complexes and covalently bonded to other sulfuratoms, including a-sulfur (orthorhombic sulfur), β-sulfur (monoclinicsulfur) and “catena” sulfur. Chains or rings of sulfur atoms can rangefrom a few sulfur atoms to hundreds of covalently linked sulfur atoms.All allotropes of elemental sulfur are suitable for use in thesulfur-extended composition. Sulfur covalently bonded with non-sulfuratoms, such as carbon, hydrogen or other atomic species, includingheterorganic compounds, is not considered “free” or elemental sulfur.Because of the wide variety of allotropes, elemental sulfur is found inmany different solid and liquid forms and can change between forms basedupon modifications to its environment, including heating and pressure.Typically, however, it is handled in either a pellet or powdered solidform or a molten liquid form.

The source of elemental sulfur can be naturally occurring (for example,mined) or a resultant from natural gas or petroleum treatment processes.For example, a well-known and understood natural gas sweetening processconverts hydrogen sulfide into elemental sulfur in a Claus unit.

Elastomer

An elastomer is technically defined as a cross-linked, amorphous polymerthat is above its glass transition (T_(g)) temperature; however, thoseof ordinary skill in the art consider elastomers as a class of polymers(thermoplastic or thermoset) that when a load is applied it will yieldand stretch (not brittle fracture like a traditional polyolefin, such asatactic polypropylene) and will return to its original form when theload is released. Elastomers tend to have reduced glass transition andmelt temperatures than plastomers and traditional polyolefins.Traditional elastomers include diene elastomers, saturated elastomers,thermoplastic elastomers and inorganic elastomers, including silicon andsulfur-based polymers. Elastomers enhance the elastic recovery capacityof the asphalt binder, which makes the asphalt binder resistant topermanent deformation.

Unsaturated thermoplastic elastomers, includingstyrene-butadiene-styrene (SBS) block copolymers, are known as usefulpolymers for inclusion in asphalt binder for modifying its thermal andphysical properties. Because they are thermoplastic, they can be blendedand incorporated with other materials, including asphalts and sulfur.The unsaturated bonds can later be cross-linked to lock in the formwhile maintaining a significant amount of elasticity. SBS is recognizedfor its performance-enhancing benefits in road paving applications. Anembodiment of the composition includes where the elastomer comprises anSBS block copolymer. An embodiment of the composition includes where theelastomer consists essentially of the SBS block copolymer.

A useful elastomer optionally has pendent functional groups from thepolymer backbone that are reactive. The reactive functional groups areoperable to react and form covalent bonds with corresponding functionalgroups on other elastomer molecules or other constituents of the SEEAB,including the free sulfur and reactive moieties in the asphalt binder.The functional groups can become reactive under different processconditions, including at elevated temperatures, in the presence of acatalyst or in an acidic or alkaline medium. Reactive functional groupsinclude primary and secondary alcohols, primary and secondary amines,acid anhydrides, epoxides and parts of other molecules that haveunsaturated carbons (that is, double and triple-bonded carbons). Anexample of a commercially available elastomeric terpolymer with pendentreaction functional units is sold under the name ELVALOY (E.I. du Pontde Nemours and Co.; Wilmington, Del.).

Forming the Sulfur-Extended Elastomer Asphalt Binder

Addition and blending of components of the SEEAB can occur in any order.A non-limiting example includes adding components individually to apre-heated and stirred asphalt binder material. Addition of the othercomponents to form the SEEAB can occur sequentially or simultaneously.

Blending occurs in a vessel or apparatus appropriate to combine all ofthe SEEAB components together. Suitable vessels and apparatuses includemetal cans with hand blenders, reactors, buckets, mixing bowls, tanksand low- or high-shear mixing processors. The blending apparatus isoperable to both maintain the base asphalt, the intermediate compositionand the formed SEEAB at a steady temperature greater than ambientconditions as well as mix the components until obtaining uniformity.Maintaining an elevated and steady temperature ensures that uponaddition of sulfur to the composition or formation of the SEEAB limitsthe likelihood of hydrogen sulfide and sulfur dioxide gas formation,which can be harmful to those individuals performing the blendingoperation. The blending apparatus is operable to induce circulation inthe molten asphalt binder and maintains any intermediate blends in amolten form to ensure the thorough incorporation of asphalt bindercomponents.

A process of forming an embodiment of the SEEAB composition includesintroducing into the suitable blending apparatus the asphalt binder usedas the base material and then heating the asphalt binder to an elastomermixing temperature. The elastomer mixing temperature is greater than150° C. and is usually maintained where the base asphalt becomes moltenand fluidic, but not much greater than that. In some cases, the baseasphalt is heated to an elastomer mixing temperature of about 180° C.The elastomer is introduced to the asphalt binder and mixed at theelastomer mixing temperature until thoroughly incorporated, forming anintermediate asphalt binder mixture. The elastomer mixing temperature isrelatively low compared to typical hot mix asphalt applications. Heat isonly applied for as long as necessary to blend the elastomer and theasphalt binder together. The risk of forming hydrogen sulfide and sulfurdioxide is low since the base asphalt does not have significantquantities of free sulfur.

Upon thorough incorporation of the elastomer, the temperature of theintermediate asphalt binder mixture cools to a sulfur mixingtemperature. The sulfur mixing temperature is in a range of from aboutthe melting point of elemental sulfur to no greater than about 145° C.Depending on the molecular configuration of the free sulfur, the meltingpoint of sulfur varies between about 120° C. and about 140° C. Uponreaching the sulfur mixing temperature, elemental sulfur is introducedand blended for an adequate period into the intermediate asphalt bindermixture until thoroughly incorporated. An embodiment of thesulfur-extended elastomer asphalt binder forms upon incorporation of thesulfur.

The SEEAB is compositionally stable. The SEEAB can be maintained at atemperature greater than ambient but no greater than 145° C. forextended periods for both exterior and interior applications.

Use of the Sulfur-Extended Elastomer Asphalt Binder

In the method of waterproofing or damp proofing, an embodiment of theSEEAB composition is applied to a surface of a protected member to forma water proof or damp proof layer. The formed layer has a first side incontact with and adhered to the surface of the protected member and asecond side that is not in contact with the surface of the protectedmember. The layer adheres to the surface of the protected member andprevents water migration through the protected member. The surface ispreferably clean; however, this is not necessary. The SEEAB isparticularly suited for applying to roof tops and roofing materialsalready in place.

SEEAB is useful as a primer for other coatings; roofing; damp-proofingand waterproofing, including adhering roofing sheets to roofs orwaterproofing coverings for roofing fabrics; and spray coating for pipesand other industrial protection schemes, including steel and iron. In anembodiment of the method, a second material is introduced to the secondside of the layer such that the layer adheres to the second material.The temperature of the layer is in a range of from about ambienttemperature to no greater than 145° C. The SEEAB is applied to walls,roofs and other surfaces using asphalt binder spreading and sprayingequipment known to one of ordinary skill in the art.

The bonding adhesion demonstrated by the SEEAB to surfaces, especiallymetal surfaces, over traditional neat asphalt and sulfur-extendedasphalt allows it not only to adhere to surfaces but also to materialsapplied to it while the composition is at a higher-than-ambienttemperature, including roofing tiles, crushed stone and aggregate, tarand waxed papers, fabrics and other materials that supportwaterproofing, damp proofing and roofing construction activities. Thebonded layer of sulfur-extended elastomer asphalt binder has a bondstrength with the surface of the protected member of at least about 150kiloNewtwons per meter squared (kN/m²) as determined using the BondStrength Test.

Forming SEEABs consume a significant amount of “waste” sulfur in alow-temperature asphalt binder application. The SEEAB used includeselemental sulfur in a range of from about 0.1% to about 10.0%, elastomerin a range of from about 0.1% to about 30.0%, and asphalt binder in arange of from about 99.8% to about 60%. In an embodiment of the method,the SEEAB consists essentially of 5.0% elemental sulfur, 5.0% theelastomer and 90.0% the asphalt binder by weight. Maintaining theapplication temperature of the SEEAB in a range of from about ambientcondition to no greater than 145° C. prevents the formation of hydrogensulfide and sulfur oxides around workers and equipment, especially inisolated and confined environments such as roof tops, basements andgenerally human-inaccessible locations.

EXAMPLE

Examples of specific embodiments facilitate a better understanding ofusing the sulfur-extended elastomer asphalt binder composition. In noway should the Examples limit or define the scope of the invention.

The asphalt binder is heated to the mixing temperature of greater than140° C. The asphalt binder for all of the example compositions is a neatPerformance Grade asphalt PG 64-10. When sulfur and an elastomer areboth part of the same experimental composition, the polymer is mixedfirst into the composition at a temperature of about 180° C. untilthoroughly incorporated, which forms an intermediate composition. Theelastomer for all of the example compositions including an elastomer isa neat styrene-butadiene-styrene (SBS) block copolymer. The intermediatecomposition is then allowed to cool to a temperature of about 140° C.,at which time free sulfur is introduced and mixed until thoroughlyincorporated. In compositions where elastomer is not part of thecomposition, the asphalt binder is heated to a temperature of no greaterthan 140° C. For all experimental compositions, a blender with a highshear mixing blade combines each component for about 5 minutes toachieve uniformity. Each of the formed experimental compositions (neatasphalt, elastomer-extended asphalt, and sulfur-extended elastomerasphalt binders) are maintained at a temperature in a range of fromabout 135° C. to about 145° C. for application and experimentation.

Each of the compositions as listed in Table 1 are by total compositionweight. For example, “+10% Elastomer” represents a composition that is10% elastomer and 90% plain or neat asphalt binder, each by total weightof the composition.

Prepared experimental compositions are evaluated for viscosity usingASTM D449 and ASTM D312 physical requirements for asphalt useful fordamp proofing, waterproofing and roofing. In addition, the experimentalcompositions are also analyzed for conformance to ASTM D4402. Forpenetration, ASTM D5 is followed. For ductility, ASTM D113 is followed.For the softening point temperature, ASTM D36 is followed. For the flashpoint, ASTM D92 is followed.

The Bond Strength Test is performed using a tensile strength testingapparatus to determine the bond strength of a sample of eachexperimental composition. The tensile strength testing apparatusmeasures the maximum stress achieved by an experimental composition thatadheres two sample testing plates together that are slowly pulled apart.

The tensile strength testing apparatus for applying the stress to eachexperimental composition has several portions. The main frame portionconsists of two-20 mm thick x 75 mm² steel blocks that are spaced at theopposing ends of four 92 mm long cylindrical steel bars. The blocks andbars form a stable equally-spaced rectangular frame. The upper block ofthe main frame has two holes to accommodate rods from the upper portiontraversing through the block. A sample grip having a wedged-like edgeslot is operable to slidably interlock with an upper sample testingplate is fixed to the upper block using a short steel rod with a springbearing. The spring bearing assists in mitigating any unnecessarycompressive force while the experimental composition is being insertedin the apparatus. The upper portion of the tensile strength testingapparatus consists of a 20 mm thick×70 mm diameter steel cylinder. Twocylindrical rods are attached to the “bottom” side of the two flat endsof the cylinder. The upper portion couples with and traverses verticallythrough the upper block of the main frame through the two holes usingthe two cylindrical rods. The upper portion rests on a bearing or springsuspending system that eliminates any additional load on the testingsample due to the weight of the upper portion. A 3.0 mm screw insertedthrough each of the two cylindrical rods proximate to the distal end ofthe steel cylinder is operable to fit into a screw bore hole presentalong the 20 mm side of the lower sample testing plate to secure it tothe upper portion. Through the “top” side of the steel cylinder ahydraulic or screw drive device (for example, a CBR Compression machine)is coupled. The force delivered by the drive device is converted into aconstant downward linear motion that acts to produce increasing tensionin the experimental composition.

The apparatus uses two 30×20×6 mm rectangular sample testing platesbonded together with the tested experimental composition to perform theBond Strength Test. The contact surface area for each sample testingplates is 600 mm². There are two sample testing plates: an “upper” and“lower” sample plate. Both testing plates are made of aluminum. Theupper sample testing plate is grooved along the length of its 30 mmsides such that the top plate is operable to slidably interlock with areceiving sample grip of the tensile strength testing apparatus. Thelower sample testing plate has a 3.0 mm diameter screw-fit hole in thecenter of each 20 mm side such that a retaining screw can brace thelower plate in its relative position. The receiving sample grip holdsthe upper sample testing plate in position while the lower sampletesting plate moves downward in a perpendicular direction to the contactsurface area as it is affixed to the two cylindrical rods of the upperportion of the tensile strength testing apparatus.

The experimental composition effectively has the dimensions of 30×20×6mm and forms within the volume of the two sample testing plates. Thetesting sample of the experimental composition is prepared using the twosample testing plates. The two sample testing plates are placedperpendicular to one another, spaced 6 mm apart from each contactsurface area and fixed into position with the aid of a retainer, forminga gap between the plates. Three sides of the gap between the two sampletesting plates are enclosed by a non-sticking paper. The experimentalcomposition is heated to a temperature sufficient for it to flow and tofill the 3600 mm³ sample volume gap without forming spaces or voidsbetween the two testing plates. The experimental composition adheres tothe contact surface area of each sample testing plate. Once the gap isfilled, the testing sample of the experimental composition and sampletesting plates cool together as an assembly before removing thenon-sticking paper. Typically, 15 minutes is sufficient for the testingsample of the experimental composition to cool to the touch andstabilize. If necessary, the assembly is cooled for 5 minutes in afreezer after waiting 30 minutes for the assembly to cool sufficientlyto peel the non-stick paper. The experimental composition assembly isthen introduced into a 25° C. water bath for at least 90 minutesdirectly before testing.

The Bond Strength Test involves loading the 3600 mm³ test sample of theexperimental composition with tension at a rate of 1.27 mm/minute at 25°C. During the Bond Strength Test, the downward motion produces anincreasing stress in the experimental composition as it attempts toremain adhered to the two sample testing plates. Load magnitude anddeformation are detected during the Bond Strength Test. The drive devicedetects the tension produced in the experimental composition as thedrive device moves at a constant rate downward. The maximum detectedforce before catastrophic bonding failure for the testing sample and thesample plate surface area is the reported bond strength. The bondstrength is presented in kiloNewtons per square meter (kN/m²).

The test results are presented in Table 1. Cells in Table 1 labeled with“X” indicate that the test was not conducted.

TABLE 1 Various properties of neat asphalt binder, elastomer-extendedasphalt binder with 0-10 wt. % elastomer, and several sulfur/elastomerextended asphalt binders with varying amounts of elastomer and sulfur.Penetration @ 25° C. under Viscosity Bond Flash Softening 100 g load for(cp) at strength Point Point Ductility 5 seconds 135° C. at 25° C.Binder Type (° C.) (° C.) (cm) (tenths of mm) (20 rpm) (kN/m2) PlainAsphalt 338 52.3 150+ 67.6 571.0 25.83 +5% Elastomer 330 86.9   14.524.1 7988 105 +10% Elastomer 330 106.9  4 21.6 >13000 X +5% Sulfur, 15081.4 24 30.5 6938 155 +5% Elastomer +5% Sulfur, 180 62 71 27.3 1500 X+3% Elastomer +10% Sulfur, X 75.5 51 41.2 X X +5% Elastomer

As Table 1 shows, the 5/95 elastomer/asphalt composition shows over a300% improvement in bond strength over plain asphalt, whereas the 5/5/90elastomer/sulfur/asphalt composition shows over 500% improvement in bondstrength using the Bond Strength Test. The dramatic increase in adhesionas shown using the Bond Strength Test with the 5/5/90elastomer/sulfur/asphalt composition over the 5/95 elastomer/asphaltcomposition (over 40%) is surprising. An embodiment of the compositionhas a bond strength of greater than 150 kN/m² as determined using theBond Strength Test.

Table 1 shows that the 5/5/90 elastomer/sulfur/asphalt composition has areduced viscosity (not greater than 7500 cP) compared to the 5/95elastomer/asphalt composition. The 5/5/90 elastomer/sulfur/asphaltcomposition is about 13% less viscous comparatively than the 5/95elastomer/asphalt composition, which makes the 5/5/90elastomer/sulfur/asphalt composition easier to work with in standardasphalt binder processing equipment. The addition of sulfur to thecomposition appears to mitigate some of the viscosity effects of addingthe elastomer.

The 5/5/90 elastomer/sulfur/asphalt composition also has an increasedductility (greater than 20 cm) as compared to the 5/95 elastomer/asphaltcomposition. The 5/5/90 elastomer/sulfur/asphalt composition is about65% more ductile than the 5/95 elastomer/asphalt composition. The5/10/85 elastomer/sulfur/asphalt composition is about 350% more ductilethan the 5/95 elastomer/asphalt composition. Higher ductility makes thebinder more resistant to cracking, which is useful as a layer forpreventing water penetration that may be exposed to environmentaleffects.

The 5/5/90 elastomer/sulfur/asphalt composition has a flash pointtemperature that is no greater than about 200° C. The same compositionalso has a softening point temperature of less than 83.0° C. and has apenetration of greater than 25 tenths of a millimeter.

What is claimed is:
 1. A sulfur-extended elastomer asphalt bindercomposition useful for water proofing, damp proofing and roofingapplications, the sulfur-extended elastomer asphalt binder compositioncomprising elemental sulfur in a range of from about 0.1% to about30.0%, an elastomer in a range of from about 0.1% to about 10.0% and theasphalt binder in a range of from about 99.8% to about 60%, each bytotal weight of the sulfur-extended elastomer asphalt bindercomposition.
 2. The composition of claim 1 where the elemental sulfur isin a range of from about 0.1% to about 10.0% and the asphalt binder isin a range of from about 99.8% to about 80%, each by total weight of thesulfur-extended elastomer asphalt binder composition.
 3. The compositionof claim 1 where the sulfur-extended elastomer asphalt bindercomposition consists essentially of 5.0% elemental sulfur, 5.0% theelastomer and 90.0% the asphalt binder, each by total weight of thesulfur-extended elastomer asphalt binder composition.
 4. The compositionof claim 1 where the asphalt binder is a Performance Grade asphalt perthe AASHTO Performance Graded Asphalt Binder Specification M 320,Table
 1. 5. The composition of claim 4 where the asphalt binder consistsessentially of a PG 64-10 asphalt cement.
 6. The composition of claim 1where the elastomer comprises a styrene-butadiene-styrene (SBS) blockcopolymer.
 7. The composition of claim 6 where the elastomer consistsessentially of a SBS block copolymer.
 8. The composition of claim 1where the composition is operable to form a layer on and bond with asurface such that the bond strength between the layer and the surface isat least 150 kN/m² as determined using the Bond Strength Test.
 9. Thecomposition of claim 1 where the composition has a ductility that is noless than 20 cm per ASTM D113.
 10. The composition of claim 1 where thecomposition has a softening point temperature of less than 83° C. perASTM D36 and has a penetration of greater than 25 tenths of a millimeterper ASTM D5.
 11. The composition of claim 1, wherein the elastomer is anunsaturated elastomer.
 12. The composition of claim 1, wherein thesulfur-extended elastomer asphalt binder forms with a viscosity that isless than the viscosity of the intermediate asphalt binder mixture andthat is no greater than 7500 cP.